[Boost-users] Re: about license

Jon Kalb writes:

On 2/24/04 5:42 PM, "David Abrahams" wrote:

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Marleny Rafferty writes:

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Hi-

I am considering using boost in my applications, but I have a question about the boost license at http://www.boost.org/LICENSE_1_0.txt . It says (edited) "Permission is hereby granted, free of charge, to ... use [and] reproduce ... the Software".

It also says that any derivative works must also have the same license grant.

If my application uses boost libraries unchanged, is it considered a derivative work?

Yes.

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If so, does that mean that if I distribute my compiled software, I must allow free of charge use and distribution?

No, the license gives an explicit exemption for compiled code (emphasis mine):

all derivative works of the Software, UNLESS SUCH COPIES OR DERIVATIVE WORKS ARE SOLELY IN THE FORM OF MACHINE-EXECUTABLE OBJECT CODE GENERATED BY A SOURCE LANGUAGE PROCESSOR.

So you're saying that "I must allow free of charge use and distribution" if my derivative work is not "solely" in the form of compiled code? If I write an application that uses the Boost sources and wish to sell it in source form with the Boost files as part of the package, I can't do it because that wouldn't be "free of charge use and distribution"?

The fact you sell your application together with sources doesn't make the combination a single "work" (IANAL).

I don't believe that is the intention of the license.

No, you're misreading it (IANAL but I know the intent). You're allowed to charge all you want, but any **non-compiled** derivative work, once you've sold it, becomes freely redistributable.

With the standard "I am not a lawyer" disclaimer, I believe what it is attempting to say is that you may not distribute the *Boost source* without this notice even if it is part of a derivative work.

Exactly.

In practice, the files that you create from scratch (for your derivative work) you may copyright and license as you wish, but the Boost files must have this license. (If you want to modify the boost files and not have your modifications covered by the license, I suppose you could call the portions of the code that are not covered by the license in the source file, but you might be on legal thin ice.)

I don't know what you're getting at here.

I'm not qualified to say if this is what the license actually means to a judge, but I believe that this is the intent.

-- Dave Abrahams Boost Consulting www.boost-consulting.com